Insulating product



Patented Jan. 2, 31934 UNETED STATES w en int owing No Drawing. Application @ctober i, 1929 Serial No. 397,460

4 Claims.

The present invention relates to improvements in the art of heat insulation, and has particular reference to a new and improved insulating product.

The primary object of the present invention resides in the provision of a new and improved heat insulating product or fibre made from amphibole.

Amphibole is a form of natural asbestos ore. In this state, it often has no appreciable fibre, and exists in the form of a crystalline dirt or powder. Some amphibole ore has a fibre, but the fibre is without tensile strength and is unfitted for use as an insulating fibre, and cannot be carded and spun. As a result, little use has been made of amphibole in the past, and its use as an insulating fibre or a base ingredient for an insulating fibre heretofore has never been considered feasible. It has been used most commonly in the manufacture of plastic floor- An important object resides in the-provision of a novel manufactured asbestos fibre made from amphibole which can be machined into a felt or batting, and can be carded and spun, which has a greater heat resisting capacity and insulation value than natural asbestos, and which in use goes further and is more economical than natural asbestos.

I will now describe one suitable process for manufacturing the fibre, but it is to be understood that the invention is not limited to any particular process.

In carrying out the process, the amphibole mined as a natural earth, either in the fibrous or non-fibrous form, is melted down. This may be accomplished in any suitable manner and in any suitable apparatus, but preferably is carried out in a retort (not shown) in the presence of a solid carbonaceous fuel, such as coal or coke, which is first mixed therewith.

Any combustible impurities in the amphibole then are burned out. This step will be carried out simultaneously with the melting of the amphibole if the latter takes place in the presence of fuel as described in the foregoing. If the amphibole is melted out of the presence of fuel, the burning out of the impurities constitutes a separate step.

After the impurities have been removed, the 6 resulting product is re-melted, preferably in an-' other suitable container, such as a second retort (not shown) The process thus far may be either a continuous process or a batch process.

The purified molten slag now is blown in any suitable manner to form a fibre. Preferably, a blast of steam is forced through a spray of the molten slag to form the fibre.

The resultant fibre is unusually tough, and has a honey-comb or cellular structure. I have found that it will withstand more heat than natural asbestos fibre, and that it has a greater insulating value than natural asbestos. I have also found that in use it will go further for a given weight than natural asbestos fibre, and that it therefore is highly efiicient and economical.

The fibre may be made into a large variety of heat insulating products. Thus, it may be machined into a felt or batting or may be carded and spun. In making a felt or batting, the fibre is impacted by a jet of air or steam under pressure against a perforated surface. Preferably the fibre is separated into a plurality of grades in accordance with variations in the specific gravity of the single fibres. The separated grades then are impacted respectively against a plurality of perforated surfaces.

I claim as my invention:

1. A manufactured asbestos fibre made from non-fibrous amphibole ore.

2. An asbestos fibre having a honey-comb structure.

3. A manufactured insulating fibre consisting of amphibole and having a honey-comb structure.

4. An insulating product comprising an amphibole slag fibre.

LOUIS WEBER. 

